An archival social and technological history of 21st Century mineral processing. Barry Wills of MEI presents news and views on mineral processing, as well as occasionally indulging his passions for travel, outdoor activities, geology, history and Cornwall.

Monday, 26 November 2012

Process Mineralogy '12 was held at the Vineyard Hotel, Cape Town, from November 7-9, 2012. The following is my diary of events, which, as always, I hope will be supplemented by comments from delegates who attended.
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Conference sponsors

﻿Wednesday November 7th
This morning I welcomed the 123 delegates from 21 countries to Process Mineralogy '12. This is the second conference in this series, and despite the recent problems on the South African mines, has attracted a record attendance and nine sponsors. This is not surprising, as process mineralogy should be of major interest to every modern mineral processor.

Three months ago I spent a day on the Nchanga mine in Zambia, my first visit since I left there nearly 40 years ago. While discussing the operations with the metallurgical staff I was interested to hear that the main copper losses from the mine were due to chalcocite. Why this was particularly interesting was that 40 years ago, despite the broad suite of minerals in the ore, there would have been no mention of a mineral, all losses being reported by chemical assay as acid soluble or acid insoluble copper. Process mineralogy was something which apparently did not exist- we did not even have a microscope on the concentrator.

Now that ores have become more complex and refractory, knowledge of process mineralogy is essential on every mine, and the tools with which we analyse the behaviour of mineral assemblages have by need become increasingly sophisticated (and expensive!). So we have a lot to look forward to over the next three days, with case studies from various operations, the emergence of new technologies, such as tomography, and the continued development of geometallurgy, the science of integrating geology and mineralogy with mineral processing and extraction.

With Megan Becker

Following my brief introduction, I had the great honour of presenting the inaugural MEI Young Person's Award to Peter Amelunxen (posting of November 7th), before introducing our process mineralogy consultant, Dr. Megan Becker, of the University of Cape Town. She talked about the changes that are taking place in the process mineralogy community and how we are generally moving in the right direction. There are some really exciting developments in the world of x-ray tomography that should enable us to really get to grips with things like routinely imaging particles in 3D, measuring coarse particle liberation, rapid scanning for minerals of interest etc.

This morning's keynote lecture, presented by Dr. Wolfgang Baum, of FLSmidth, USA, set the scene perfectly for the day's papers on process case studies. Entitled "Ore characterization, process mineralogy and lab automation - a roadmap for future mining" he looked at the upstream requirements of process mineralogy in the future. Some mineralogical and chemical laboratories are making the step change toward automation, but the use of automated mineral analysis and high-throughput mineralogical ore profiling in production requires a faster pace. Cross belt neutron analyzers, over-the-belt NIR and, eventually, on-line XRD systems will become important for competitive ore processing. The mines of the future may be outfitted with down-hole probes and on-site automated mineralogy modules. Robust and rigorous use of automated laboratories and cross-belt technology will be the new frontier for process mineralogy.

With Byron Bezuidenhout (South Africa), Musarrat Safi (South Africa),
Friederike Minz (Sweden) and Tobias Salge (Germany) who were presenting
papers for the first time at an international conference

The morning session continued with case studies on mineral processing operations including an extension of process mineralogy to the processing of waste.

After an excellent Vineyard lunch, the afternoon session was dominated by 4 case studies from Anglo American Technical Solutions, a major user of automated mineralogy systems. Of the other four papers, there was an interesting one from Norway on the effect of sulfides on the whiteness in paper production, highlighting how process mineralogy is diversifying.

Thursday November 8th
The rapid development in sophisticated mineralogical techniques was highlighted in today's papers, led by an excellent keynote lecture by Prof. Jan Miller, of the University of Utah, who set the scene by showing how X-ray tomography has progressed from the late 20th century to the present day. He stressed that appropriate education and training of young scientists in this area is necessary to develop the advanced skills for future development and applications. What is encouraging in this respect is the high proportion of young people attending the conference, which bodes well for the future.

It is only four years since our last annual Automated Mineralogy conference in Brisbane. At that time the only mineralogical SEMs generally available were the JKTech's Mineral Liberation Analyser (MLA) and Intellection's QEMSEM and QEMSCAN. Intellection went into receivership shortly after Automated Mineralogy '08 and QEMSEM/SCAN were taken over by FEI, who now also market the MLA.

The FEI booth

Conference sponsor FEI is a premier provider of electron- and ion-beam microscopes and solutions for applications across many industries. The company is displaying the recently introduced MLA EXpress™, a low-cost, bench-top, automated mineralogy analyzer that may enable the mining industry to maximize the recovery of valuable metals from the ore. MLA EXpress extends mineral liberation analysis to a broader scale of mining operations.

Major changes in recent years include developments in the technical capabilities of automated mineralogy and associated techniques, and the growth in the number of instrument manufacturers.

This is the first time that the Czech company TESCAN has attended an MEI Conference, and their sponsorship of this one highlights how they are building a reputation in designing, manufacturing and selling scanning electron microscopes and system solutions for different applications, currently having over 1300 SEM installations in more than 60 countries.

Oxford Instruments is another company sponsoring an MEI Conference for the first time. Building on more than 20 years of experience in Scanning Electron Microscope-based Mineral Liberation Analysis, the company is exhibiting INCAMineral, an Automated Mineral Liberation Analysis solution
for multipurpose SEMs. This combines the functionality expected from a dedicated automated mineralogy system with the flexibility of a SEM.

Oxford Instruments

﻿﻿﻿﻿Automated techniques for mineral classification, liberation analysis and textural analysis featured strongly in the afternoon session, which included a paper from Carl Zeiss Microscopy Ltd, presenting an SEM solution based on a fully automated mineralogical tool, MineraLogic, that performs the characterisation, classification and quantification of ash minerals. MineraLogic was on display at the conference and generated much interest. ﻿

Demonstration of MineraLogic

﻿After two intensive days it was good to relax with delegates at the Gold Restaurant in the city, for a very informal African themed conference dinner (see also posting of 9th November).

Friday 9th November
Geometallurgy was the theme of the 10 papers presented in this morning's session, which included two presentations on rare earths beneficiation from South Africa's Mintek and conference sponsor SGS.

The SGS booth

The final sesion dealt with the tools of process mineralogy. Prof. Johan de Villiers of the University of Pretoria showed that the most common methods for generating mineralogical information of relevance to the minerals and metallurgical industry are usually in the order: optical microscopy, XRD analysis and Quantitative SEM analysis. These are usually generated by persons skilled in one of these techniques. As a consequence, the results of the other techniques are often overlooked or neglected. He discussed the applicability of each of the methods and their strengths and weaknesses. Conference sponsors PANalytical and Bruker AXS presented interesting papers, the former showing how X-ray diffraction can be used for process optimisation, and Bruker how XRD, XRF and MLA have been combined to analyse an iron ore.

At the PANalytical booth

The Bruker AXS booth

Megan Becker and Amanda closed the conference, and invited delegates to attend Process Mineralogy '14, which will be held at the same venue from November 17-19, 2014. Then it was out into the sunshine for yet more wine
and final farewells.

All 57 papers presented at the conference are available on CD from MEI.

12 comments:

Judging from the 44 papers and 12 poster presentations delivered at MEI’s Process Mineralogy ’12, the future of Modern Process Mineralogy looks secure. The two keynote speakers, Baum and Miller, delivered useful lectures on the overall modern best practice, and on the emerging technology now available in tomography. The younger authors presented a very high standard of work with new thinking. The overall standard presented was very high, with useful case studies demonstrating value delivery in projects – now including extractive metallurgy, and some new methods under development to add to the Process Mineralogy toolbox. Good examples of the latter were the proposal by Wightman and Evans on a quantitative liberation model for grinding requirements; by Evans and Napier-Munn on estimating the error of grain size measurements; and an outstanding contribution by Pérez-Barnuevo on the development of a quantitative model to characterise the complexity of composite particles. By my book, an international conference worthy of putting on one’s “must attend” list into the future. MEI, the organising committee, and contributing authors deserve compliments for such a strong presentation.

Thank you and the MEI team for a successful and interesting Process Mineralogy 2012 conference. I am glad that I attended the conference. It is always great to return to South Africa and to catch up with friends and ex-colleagues, and also meet new people working in the field. Some interesting papers were presented at the conference. In my opinion, the paper presented by Laura Perez Barnuevo was probably the best. I hope that Laura will publish her findings and I am sure that she will have a future in process mineralogy. Dr Hanna HorschManager, Quantitative MineralogyHazen Research, Inc.,USA

Thank you once again to the MEI team for putting on an outstanding conference. I'm also really proud of all the presenters for the high quality of the presentations and the discussions that followed (especially the PhD students). I agree with Hanna that Laura's paper was one of the best - and hope to see the outputs of her work becoming routinely available in the automated mineralogy software in the future. It was great to catch up with old acquaintances and also make some news ones.

The use of automated technologies for the characterization of mineral particles is nowadays widespread. However, most of these techniques do not currently quantify some textural features, whose characterization is essential to improve and predict the performance of mineralurgical processes and to achieve a complete and accurate geometallurgical model.

In this paper, a new methodology based on digital image analysis is presented to automatically characterize the type of intergrowth between mineral phases within particles. This method has been applied to the analysis of the Kansanshi Copper ore. In this ore, chalcopyrite is usually surrounded by a rim of secondary copper sulfides or densely veined by them, causing copper loss in the flotation tails. Results show that the method identifies correctly the type of intergrowth in most cases and provides a quantitative characterization of this feature along with other valuable mineralogical information, contributing to a better knowledge of the ore behaviour.

Thank you for a well-organised conference which I thoroughly enjoyed. It was great to see what everyone is busy with and my students gained an appreciation of what the world of Process Mineralogy is all about.

As the conference expands it will become increasingly necessary to resort to poster sessions in order to accommodate all contributors. The poster area at the conference was a bit cramped and it would be great if more space could be assigned to it.

Prof Fanus ViljoenDST Research Chair in GeometallurgyUniversity of JohannesburgSouth Africa

The conference was an excellent opportunity to interact with other mineralogists working in different areas of the field. It also provided great insight on the directions in which process mineralogy is moving. I particularly enjoyed the talks on the progress that is being made in X-ray tomography!

This conference has developed into a leading forum for Process Mineralogy. My thanks go to the MEI team for a well-organized meeting. The quality of the papers was very good. For future meetings, I suggest to enlist more papers from Mineralogy Use in processing plants and/or operational experiences in heap-stockpile leaching. This will help to increase the value of the conference for operators and expand the acceptance of daily process mineralogy.

Many thanks to the MEI team for organizing this great conference. For me, as a young researcher getting involved in Process Mineralogy, it was encouraging and motivating attending the conference and interacting with other people working in the field. I would also like to thank everyone who showed interest in my presentation because it encourages me to keep improving my work.

Many thanks for such a well-organised conference. I particularly appreciated the opportunity to interact with other mineralogists and catch up with many of the advances that have been made in the application of proess mineralogy techniques. Also, the chance to discuss aspects of environmental mineralogy and link up with other researchers within that field has proved invaluable.

Well done to the organising committee for hosting another successful Process Mineralogy conference. My interest in new analytical techniques, the industrial application thereof and process mineralogy case studies was certainly satisfied. Like many other I followed the discussions regarding X-ray tomography keenly and hopefully soon we will be able to determine the potential application of this technology for the heavy mineral industry. Once again thank you for providing the opportunity to increase my knowledge.